The invention relates to a fish farm designed to be located in deep sea, and designed for intensive production of fish, constituted by a cultivation cage (1) designed to be submerged and kept at a considerable depth, provided with ballast tanks (6) which allow the adjustment of such depth, adjusting same to the suitable temperature level of the water, the upper end of such cultivation cage (1) extending into a hollow column (7), with a minimum floating area, and which is provided on its upper end with a tower (8) containing the personnel facilities and which projects from the surface of the water likewise being kept outside the scope of influence of the waves, as is the case of the lower cultivation cage (1), wherefore the stability of the fish farm is maximum.